Smoking is the leading preventable cause of morbidity and mortality worldwide. Cessation of smoking significantly reduces the risk of dying from tobacco-related diseases such as oral cancer, heart diseases, and lung cancer. Since smoking is considered to be a major health hazard in the world, dentists and health-care workers need to consider it seriously and assist their patients in smoking cessation. This review article summarizes different smoking cessation methods, withdrawal symptoms and health benefits due to smoking cessation.

Smoking is a practice in which a substance is burned and the resulting smoke is breathed in to be tasted and absorbed into the bloodstream. Smoking is primarily practiced as a route of administration for recreational drug use as the combustion of the dried plant leaves vaporizes and delivers active substances into the lungs where they are rapidly absorbed into the bloodstream and reach bodily tissue. Most commonly used substance for smoking is the dried leaves of the tobacco plant which are rolled into a small square of rice paper to create a small, round cylinder called a "cigarette". Cigarettes are primarily manufactured by industry but also can be hand-rolled from loose tobacco and rolling paper. Other smoking implements include pipes, cigars, bidis, hookahs, vaporizers, and bongs.

Smoking Cessation

The process of discontinuing tobacco smoking is called smoking cessation. Nicotine of tobacco is addictive, [1] which makes the process of quitting very prolonged and difficult. Seventy percent of smokers would like to quit smoking, and 50% report attempting to quit within the past year. [2]

Methods of Smoking Cessation

Many different methods can be used for smoking cessation which includes quitting without assistance such as cold turkey or cut down then quit, medications such as nicotine replacement therapy (NRT) or varenicline, and behavioral counseling. The majority of smokers who try to quit do so without assistance, though only 3-6% of quit attempts without assistance are successful. [3] the use of medications and behavioral counseling both increase the success rates, and a combination of both medication and behavioral interventions has been shown to be even more effective. [4] Different methods for smoking cessation are shown in [Table 1].

Five medications approved by the US Food and Drug Administration (FDA) deliver nicotine in a form that does not involve the risks of smoking. NRT are used for a short period of time and should be tapered down to a low dose before stopping. The five NRT medications for smoking cessation are shown in [Figure 1]: [6]

First-line medication for smoking cessation. It has shown in many studies to increase long-term success rates. People who take bupropion should be monitored for any unusual mood hanges. Bupropion also increases the risk of seizures, and it should not be used in people with a seizure disorder.

Nortriptyline

It has also been shown to increase smoking cessation success rates. Other antidepressants such as selective serotonin reuptake inhibitors and St. John's wort have not been consistently shown to be effective for smoking cessation. [7]

Varenicline

It decreases the urge to smoke and reduces withdrawal symptoms and is therefore considered a first-line medication for smoking cessation. [8]

A systematic review found that varenicline had higher success rates than bupropion. [7] A 2011 Cochrane review of 15 studies also found that varenicline was significantly superior to bupropion at 1 year but that varenicline and nicotine patches produced the same level of abstinence at 24 weeks. [9] A 2011 review of double-blind studies found that varenicline has increased the risk of serious adverse cardiovascular events compared with placebo. [10] Varenicline may cause neuropsychiatric side effects; for example, in 2008 the UK Medicines and Healthcare products Regulatory Agency issued a warning about possible suicidal thoughts and suicidal behavior associated with varenicline. [11]

Clonidine

It may reduce withdrawal symptoms and "approximately doubles abstinence rates when compared to a placebo," but its side effects include dry mouth and sedation and abruptly stopping the drug can cause high blood pressure and other side effects. [12],[13]

Psychedelic mushrooms

Studies indicate an 80% success rate from consuming psychedelic mushrooms when it is administered after careful preparation and in a therapeutic context, psilocybin can lead to deep reflection about one's life and spark motivation to change. [14]

Cut down to quit

Gradual reduction involves slowly reducing one's daily intake of nicotine. This can theoretically be accomplished through repeated changes to cigarettes with lower levels of nicotine by gradually reducing the number of cigarettes smoked each day or by smoking only a fraction of a cigarette on each occasion. A 2009 systematic review by researchers at the University of Birmingham found that gradual NRT could be effective in smoking cessation. [15],[16] There is no significant difference in quit rates between smokers who quit by gradual reduction or abrupt cessation as measured by abstinence from smoking of at least 6 months from the quit day, suggesting that people who want to quit can choose between these two methods. [17]

Set a quit plan and quit date

Most smoking cessation resources such as the CDC [18] and Mayo Clinic [19] encourage smokers to create a quit plan, including setting a quit date, which helps them in planning ahead for challenges from smoking cessation. A quit plan can improve a smoker's chance of a successful quit [20],[21],[22] as can as setting Monday as the quit date, given that research has shown that Monday more than any other day is when smokers are seeking information online to quit smoking [23] and calling state quitlines. [24]

Community interventions

A Cochrane review found evidence that community interventions using "multiple channels to provide reinforcement, support, and norms for not smoking" had an effect on smoking cessation outcomes among adults. [25] Specific methods used in the community to encourage smoking cessation among adults include:

Policies making workplaces and public places smoke-free. It is estimated that "comprehensive clean indoor laws" can increase smoking cessation rates by 12-38%. [26] In 2008, the New York State of Alcoholism and Substance Abuse Services banned smoking by patients, staff, and volunteers at 1300 addiction treatment centers [27]

Voluntary rules making homes smoke-free, which will help in promoting smoking cessation [28]

Initiatives to educate the people regarding the health effects of second-hand smoke

Increasing the price of tobacco products, for example, by taxation. The US Task Force on Community Preventive Services found "strong scientific evidence" that it is effective in increasing tobacco use cessation. [29] It is estimated that an increase in price of 10% will increase smoking cessation rates by 3-5% [26]

Mass media campaigns. The US Task Force on Community Preventive Services declared that "strong scientific evidence" existed for these when "combined with other interventions" [29] but a Cochrane review concluded that it was "difficult to establish their independent role and value." [30]

Psychosocial approaches

Great American Smokeout is an annual event that invites smokers to quit for 1 day, hoping they will be able to extend this forever

The World Health Organization's World No Tobacco Day is held on May 31 each year

Smoking-cessation support is often offered over the internet, over the telephone quitlines [31],[32] (e.g., the US toll-free number 1-800-QUIT-NOW), or in person. Three meta-analyses have concluded that telephone cessation support is effective when compared with minimal or no counseling or self-help and that telephone cessation support with medication is more effective than medication alone [33]

Group or individual psychological support can help people who want to quit. This form of counseling can be effective alone; combining it with medication is more effective, and the number of sessions of support with medication correlates with effectiveness. [34],[35] The counseling styles that have been effective in smoking cessation activities include motivational interviewing, [36],[37],[38] cognitive behavioral therapy, [39] and acceptance and commitment therapy [40]

The freedom from smoking group clinic includes eight sessions and features a step-by-step plan for quitting smoking. Each session is designed to help smokers gain control over their behavior. The clinic format encourages participants to work on the process and problems of quitting both individually and as a part of a group [41]

The transtheoretical model including "stages of change" has been used in tailoring smoking cessation methods to individuals. [42],[43],[44],[45] However, a 2010 Cochrane review concluded that "stage-based self-help interventions and individual counseling were neither more nor less effective than their nonstage-based equivalents." [46]

Self-help

Self-help modalities for smoking cessation include the following:

In-person self-help groups such as nicotine anonymous [47],[48],[49] or electronic self-help groups such as stomp it out [50]

Newsgroups: The Usenet group alt.support.stop-smoking has been used by people quitting smoking as a place to go to for support from others [51]

Interactive web-based and stand-alone computer programs and online communities which assist participants in quitting. For example, "quit meters" keep track of statistics such as how long a person has remained abstinent. [52] In the 2008 US Guideline, there was no meta-analysis of computerized interventions, but they were described as "highly promising. " A meta-analysis published in 2009, [53] a Cochrane review published in 2010, [54] and a 2011 systematic review [55] found the evidence base for such interventions weak

Spirituality: In one survey of adult smokers, 88% reported a history of spiritual practice or belief, and of those more than three-quarters were of the opinion that using spiritual resources may help them quit smoking. [59]

Biochemical feedback

Various methods exist which allow a smoker to see the impact of their tobacco use, and the immediate effects of quitting. Using biochemical feedback methods can allow tobacco-users to be identified and assessed, and the use of monitoring throughout an effort to quit can increase motivation to quit. [60],[61]

Breath carbon monoxide monitoring: because carbon monoxide (CO) is a significant component of cigarette smoke, a breath CO monitor can be used to detect recent cigarette use. CO concentration in breath has been shown to be directly correlated with the CO concentration in blood known as percent carboxyhemoglobin. The value of demonstrating blood CO concentration to a smoker through a noninvasive breath sample is that it links the smoking habit with the physiological harm associated with smoking. [62] Within hours of quitting, CO concentrations show a noticeable decrease, and this can be encouraging for someone working to quit. Breath CO monitoring has been utilized in smoking cessation as a tool to provide patients with biomarker feedback, similar to the way in which other diagnostic tools such as the stethoscope, the blood pressure cuff, and the cholesterol test have been used by treatment professionals in medicine [63]

Cotinine: A metabolite of nicotine, cotinine is present in smokers. Like CO a cotinine test can serve as a reliable biomarker to determine smoking status. [64] Cotinine levels can be tested through urine, saliva, blood, or hair samples, with one of the main concerns of cotinine testing being the invasiveness of typical sampling methods.

While both measures offer high sensitivity and specificity, they differ in usage method and cost. As an example, breath CO monitoring is noninvasive, while cotinine testing relies on a bodily fluid. These two methods can be used either alone or together, for example, in a situation where abstinence verification needs additional confirmation. [65]

Competitions and incentives

One 2008 Cochrane review concluded that "incentives and competitions have not been shown to enhance long-term cessation rates." A different 2008 Cochrane review found that one type of competition, "Quit and Win," did increase quit rates among participants. [66]

Health-care systems

Interventions delivered via health-care providers and health-care systems have been shown to help in smoking cessation among people who visit those providers.

"Multicomponent interventions were defined as those that combined two or more of the following strategies known as the '5 As':" [25],[26],[27],[28],[29],[30]

Ask - Systematically identify all tobacco users at every visit

Advise - Strongly urge all tobacco users to quit

Assess - Determine willingness to make a quit attempt

Assist - Aid the patient in quitting (provide counseling-style support and medication)

NRT includes products that contain nicotine but not a tobacco to aid cessation of smoking. These include nicotine lozenges that are sucked, nicotine gum and inhalers, nicotine patches, as well as electronic cigarette. In 2014 The Royal College of Physicians in London published an article advocating the use of electronic cigarettes as a smoking cessation tool. [67] Chewing cinnamon sticks or gum has been recommended when trying to quit the use of tobacco [Figure 2]. [68]

Alternative approaches

Acupuncture

Acupuncture has been explored as an adjunct treatment method for smoking cessation. [69]

Aromatherapy

A 2006 book reviewing the scientific literature on aromatherapy identified only one study on smoking cessation and aromatherapy; the study found that "inhalation of vapor from black pepper extract reduces smoking withdrawal symptoms." [70]

Hypnosis

Hypnosis involves the hypnotherapist suggesting to the patient the unpleasant outcomes of smoking. [71] Clinical trials studying hypnosis and hypnotherapy as a method for smoking cessation have been inconclusive; [72],[73],[74] however, a randomized trial published in 2008 found that hypnosis and nicotine patches "compares favorably" with standard behavioral counseling and nicotine patches in 12-month quit rates. [75]

Herbs

Many herbs have been studied as a method for smoking cessation, including lobelia and St John's wort. [76] The results are inconclusive, but St. John's wort shows few adverse events. Lobelia has been used to treat respiratory diseases like asthma and bronchitis and has been used for smoking cessation because of chemical similarities to tobacco; lobelia is now listed in the FDAs Poisonous Plant Database. [77] Lobelia can still be found in many products sold for smoking cessation and should be used with caution.

Smokeless tobacco

There is little smoking in Sweden, which is reflected in the very low cancer rates for Swedish men. The use of snus (a form of steam-pasteurized, rather than heat-pasteurized, air-cured smokeless tobacco) is an observed cessation method for Swedish men and even recommended by some Swedish doctors. [78]

Smoking during pregnancy can cause adverse health effects in both the woman and the fetus. The 2008 US Guideline determined that "person-to-person psychosocial interventions" increased abstinence rates in pregnant women who smoke to 13.3%, compared with 7.6% in usual care. Mothers who smoke during pregnancy have a greater tendency toward premature births. Their babies are often underdeveloped, have smaller organs, and weigh much less compared with the normal baby. In addition, these babies have worse immune systems, making them more susceptible to many diseases in early childhood, such as middle ear inflammations and asthmatic bronchitis which can bring about a lot of agony and suffering. As well, there is a high chance that they will become smokers themselves when grown up. It is a widely spread myth that a female smoker can cause harm to her fetus by quitting immediately upon discovering that she is with child. Though this idea does seem to follow logic, it is not based on any medical study or fact. [81]

Withdrawal Symptoms Due to Smoking Cessation

Because nicotine is addictive, quitting smoking leads to symptoms of nicotine withdrawal such as craving, anxiety and irritability, depression, and weight gain. [82] Professional smoking cessation support methods generally endeavor to address both nicotine addiction and nicotine withdrawal symptoms [Figure 3].

Tobacco's detrimental health effects can be reduced or largely removed through smoking cessation. The health benefits over time of stopping smoking include [Figure 3]: [83]

Within 20 min after quitting, blood pressure and heart rate decrease

Within 12 h, CO levels in the blood decrease to normal

Within 48 h, nerve endings and sense of smell and taste both start recovering

Within 3 months, circulation and lung function improve

Within 9 months, there are decreases in cough and shortness of breath

Within 1 year, the risk of coronary heart disease is cut in half

Within 5 years, the risk of stroke falls to the same as a nonsmoker and the risks of many cancers such as mouth, throat, esophagus, bladder, and cervix decrease significantly

Within 10 years, the risk of dying from lung cancer is cut in half, [84] and the risks of larynx and pancreas cancers decrease

Within 15 years, the risk of coronary heart disease drops to the level of a nonsmoker

Lowered risk for developing chronic obstructive pulmonary disease.

Conclusion

Smoking cessation is always beneficial for health. The common notion among the people who smoke is that they might feel more miserable when they discontinue the smoking, but the current evidence clearly suggests that smoking cessation will result in a healthier mental and physical health. With the appropriate use of pharmacotherapy such as NRT, there is a huge chance of successfully quitting. However, evidence suggests that a combination of psychotherapy and medication will have a higher chance of success than either of them taken alone.